Kartik Arora | IIT Bombay (original) (raw)

Papers by Kartik Arora

Research paper thumbnail of Efficient computation of the eigenspectrum of viscoelastic flows using submatrix-based transformation of the linearized equations

Journal of Non-Newtonian Fluid Mechanics, 2002

Linear stability analysis of incompressible viscoelastic flows based on normal mode expansions of... more Linear stability analysis of incompressible viscoelastic flows based on normal mode expansions of the eigenfunctions requires the numerical solution of a generalized eigenvalue problem (GEVP). The complex boundary layer structure of the leading eigenfunctions and the singular character of the continuous set of eigenvalues, necessitate the use of fine mesh sizes, leading to large algebraic GEVPs. In this paper, we

Research paper thumbnail of The influence of finite extensibility on the eigenspectrum of dilute polymeric solutions

Journal of Non-Newtonian Fluid Mechanics, 2005

Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P con... more Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P constitutive equation has been examined. Specifically, the spurious, discrete and continuous spectra are identified as a function of the ratio of the solvent to the total viscosity β, maximum chain length L, disturbance wavenumber α and the Weissenberg number (We). It is observed that reducing L

Research paper thumbnail of Surfactant-induced effects on turbulent swirling flows

Research paper thumbnail of Surfactant-induced effects on turbulent swirling flows

Research paper thumbnail of Hydrodynamic stability of unidirectional shear flow of linear and branched polymeric melts

Journal of Non-Newtonian Fluid Mechanics, 2004

In this study, the linear stability of homogeneous shear flow of polymer melts has been investiga... more In this study, the linear stability of homogeneous shear flow of polymer melts has been investigated by using a prototypical reptation-based model, namely, the Pompom model [1]. The hydrodynamic stability characteristics of the flow have been determined by using an eigenvalue analysis. Particular attention has been paid to accurate determination of the discrete and continuous eigenvalues as well as identification

Research paper thumbnail of Experimental investigation of purely elastic instabilities in periodic flows

Journal of Non-Newtonian Fluid Mechanics, 2002

Purely elastic instabilities in the flows of polyisobutylene-based Boger fluids in the periodic c... more Purely elastic instabilities in the flows of polyisobutylene-based Boger fluids in the periodic channel (PC) and past a (linear) periodic array of closely spaced cylinders (PAC) in a channel have been experimentally examined. The test geometries have the same wavelength and amplitude associated with the periodic variation in the cross-sectional area. Pressure measurements show temporal fluctuations that appear when the

Research paper thumbnail of A viscoelastic flow instability near the solid body rotation limit

Journal of Non-Newtonian Fluid Mechanics, 2005

Global linear stability analysis of the creeping flow of an Oldroyd-B liquid, confined between ec... more Global linear stability analysis of the creeping flow of an Oldroyd-B liquid, confined between eccentric cylinders co-rotated at equal angular speeds Ω, is performed using a submatrix-based transformation algorithm [K. Arora, R. Sureshkumar, J. Non-Newtonian Fluid Mech. 104 (2002) 75]. The eccentricity parameter ɛ is defined as the ratio of the distance between the cylinder centers to the average gap

Research paper thumbnail of PCIM: a physically based continuous short-channel IGFET model for circuit simulation

IEEE Transactions on Electron Devices, 1994

We present an accurate analytical IGFET model (PCIM), for short-channel devices down to sub-half ... more We present an accurate analytical IGFET model (PCIM), for short-channel devices down to sub-half micron channel lengths. The model is described by a single drain current equation, valid for both weak and strong inversion regions of device operation. The model contains a new velocity-field (v-E) relation for carriers in the channel region. Combining this relation with the channel length modulation expression, obtained using engineering approximations to the two-dimensional fields near the drain end in saturation, results in an accurate drain conductance equation. The value for the carrier saturated velocity extracted from the I-V data for different CMOS technologies is 7-23 x106 cm/s for electrons and 5-6 x106 c d s for holes, consistent with the reported values. The model not only predicts accurate output conductance, which is important for analog design, but also accurately simulates intrinsic gate capacitances for short channel devices. Since the model is inherently continuous, device conductances and capacitances are smooth and continuous at the transition points. This continuity results in enhanced convergence properties of the circuit simulator SPICE. Bemuse the model is physically based, the temperature dependence of device characteristics in the temperature range 0-120°C can easily be predicted simply by taking the temperature dependence of the threshold voltage, carrier mobility and velocity sahu'cltion parameters.

Research paper thumbnail of Modeling and extraction of interconnect capacitances for multilayer VLSI circuits

IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 1996

Research paper thumbnail of The influence of finite extensibility on the eigenspectrum of dilute polymeric solutions

Journal of Non-newtonian Fluid Mechanics, 2005

Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P con... more Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P constitutive equation has been examined. Specifically, the spurious, discrete and continuous spectra are identified as a function of the ratio of the solvent to the total viscosity β, maximum chain length L, disturbance wavenumber α and the Weissenberg number (We). It is observed that reducing L

Research paper thumbnail of Efficient computation of the eigenspectrum of viscoelastic flows using submatrix-based transformation of the linearized equations

Journal of Non-Newtonian Fluid Mechanics, 2002

Linear stability analysis of incompressible viscoelastic flows based on normal mode expansions of... more Linear stability analysis of incompressible viscoelastic flows based on normal mode expansions of the eigenfunctions requires the numerical solution of a generalized eigenvalue problem (GEVP). The complex boundary layer structure of the leading eigenfunctions and the singular character of the continuous set of eigenvalues, necessitate the use of fine mesh sizes, leading to large algebraic GEVPs. In this paper, we

Research paper thumbnail of The influence of finite extensibility on the eigenspectrum of dilute polymeric solutions

Journal of Non-Newtonian Fluid Mechanics, 2005

Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P con... more Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P constitutive equation has been examined. Specifically, the spurious, discrete and continuous spectra are identified as a function of the ratio of the solvent to the total viscosity β, maximum chain length L, disturbance wavenumber α and the Weissenberg number (We). It is observed that reducing L

Research paper thumbnail of Surfactant-induced effects on turbulent swirling flows

Research paper thumbnail of Surfactant-induced effects on turbulent swirling flows

Research paper thumbnail of Hydrodynamic stability of unidirectional shear flow of linear and branched polymeric melts

Journal of Non-Newtonian Fluid Mechanics, 2004

In this study, the linear stability of homogeneous shear flow of polymer melts has been investiga... more In this study, the linear stability of homogeneous shear flow of polymer melts has been investigated by using a prototypical reptation-based model, namely, the Pompom model [1]. The hydrodynamic stability characteristics of the flow have been determined by using an eigenvalue analysis. Particular attention has been paid to accurate determination of the discrete and continuous eigenvalues as well as identification

Research paper thumbnail of Experimental investigation of purely elastic instabilities in periodic flows

Journal of Non-Newtonian Fluid Mechanics, 2002

Purely elastic instabilities in the flows of polyisobutylene-based Boger fluids in the periodic c... more Purely elastic instabilities in the flows of polyisobutylene-based Boger fluids in the periodic channel (PC) and past a (linear) periodic array of closely spaced cylinders (PAC) in a channel have been experimentally examined. The test geometries have the same wavelength and amplitude associated with the periodic variation in the cross-sectional area. Pressure measurements show temporal fluctuations that appear when the

Research paper thumbnail of A viscoelastic flow instability near the solid body rotation limit

Journal of Non-Newtonian Fluid Mechanics, 2005

Global linear stability analysis of the creeping flow of an Oldroyd-B liquid, confined between ec... more Global linear stability analysis of the creeping flow of an Oldroyd-B liquid, confined between eccentric cylinders co-rotated at equal angular speeds Ω, is performed using a submatrix-based transformation algorithm [K. Arora, R. Sureshkumar, J. Non-Newtonian Fluid Mech. 104 (2002) 75]. The eccentricity parameter ɛ is defined as the ratio of the distance between the cylinder centers to the average gap

Research paper thumbnail of PCIM: a physically based continuous short-channel IGFET model for circuit simulation

IEEE Transactions on Electron Devices, 1994

We present an accurate analytical IGFET model (PCIM), for short-channel devices down to sub-half ... more We present an accurate analytical IGFET model (PCIM), for short-channel devices down to sub-half micron channel lengths. The model is described by a single drain current equation, valid for both weak and strong inversion regions of device operation. The model contains a new velocity-field (v-E) relation for carriers in the channel region. Combining this relation with the channel length modulation expression, obtained using engineering approximations to the two-dimensional fields near the drain end in saturation, results in an accurate drain conductance equation. The value for the carrier saturated velocity extracted from the I-V data for different CMOS technologies is 7-23 x106 cm/s for electrons and 5-6 x106 c d s for holes, consistent with the reported values. The model not only predicts accurate output conductance, which is important for analog design, but also accurately simulates intrinsic gate capacitances for short channel devices. Since the model is inherently continuous, device conductances and capacitances are smooth and continuous at the transition points. This continuity results in enhanced convergence properties of the circuit simulator SPICE. Bemuse the model is physically based, the temperature dependence of device characteristics in the temperature range 0-120°C can easily be predicted simply by taking the temperature dependence of the threshold voltage, carrier mobility and velocity sahu'cltion parameters.

Research paper thumbnail of Modeling and extraction of interconnect capacitances for multilayer VLSI circuits

IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 1996

Research paper thumbnail of The influence of finite extensibility on the eigenspectrum of dilute polymeric solutions

Journal of Non-newtonian Fluid Mechanics, 2005

Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P con... more Linear stability of plane Couette flow of dilute polymeric solutions modeled using the FENE-P constitutive equation has been examined. Specifically, the spurious, discrete and continuous spectra are identified as a function of the ratio of the solvent to the total viscosity β, maximum chain length L, disturbance wavenumber α and the Weissenberg number (We). It is observed that reducing L